How to test the BB level?

[willsmith]

If i blow air into a plastic bottle(say a 2litre pepsi bottle) and then I smell the air inside the bottle, would that be any relevant?

[wnaysha]

hi willsmith,

I like ur name, lol.

I don't know if u can smell ur breath like that, but if u want to try it, use a straw so that the oxygen and other gasses goes out of the bottle and the only thing in the bottle is ur breath.